1. Field of the Invention
This invention relates to pulse generators and more particularly to an improved pulse generator for supplying high current pulses.
2. Description of the Prior Art
Such pulse generators are especially needed in telephone switching networks of the types employing magnetic latching reed relays as crosspoints. In these types of networks, control windings of the magnetic latching reed relays are arranged in a matrix array. A selected relay is operated by applying a current pulse to a corresponding path through the matrix arrangement.
One problem that has been encountered is to supply relatively high current pulses from a pulse generator operating from a telephone central office power source. This problem may be understood by the following illustrative example. Certain reed relays require operate current pulses of approximately 5.8 amperes; the impedance presented by control paths through a matrix arrangement of control windings is 12 ohms; and the central office power source is nominally -50 volts.
Certain prior art pulse generator circuits operating from -50 volts are such that only a 4 ampere current pulse can be supplied to a 12 ohm load. Other pulse generator circuit arrangements for supplying higher current pulses have been suggested, for example, as shown in U.S. Pat. No. 3,564,297 issued to P. Elsner. However, these circuit arrangements employ relatively expensive transformers or inductors to increase the effective operating voltage of the pulse generator.